I've been trying to find the answer for a couple days now but to no avail. I think I ordered my fuel pump too small so I'm trying to find a rough estimate of turbo flow rates at 25psi and 30psi. I ordered a 255hp and am rewiring it for the most output. According to this... http://www.dsmtuners.com/threads/x-hp-which-fuel-injectors.393264/ ... that combination is good for 67.80lbs/min. If my math is correct 43.5psi base fuel pressure + 25psi boost = a total of 68.5lbs/min. Does this mean that my daily goal of 25psi is already maxing out the pump? Or am I over thinking this whole thing and confusing myself?

The hta green is rated at 57 lb min, most likey needing over 30psi maxed out with high boost on e85 or race fuel to reach that flow. A rewired 255 will handle an new hta green on 91/93 gas no problem.

So basically I'm just over thinking things and confusing myself? I tried my bestto build the fuel system around the turbos max flow but I never took the 1:1 rising rate into account and thought that maybe I screwed the pooch on pump selection.

The fuel pump chart in the link you posted above shows a rewired walbro 255 at 25 psi boost pressure (43.5 base fuel pressure+25 psi boost) supporting 59.5 lb min of flow. If you are planning on staying on gasoline and not e85 some 1000 cc injectors and a rewired 255 will work for the turbo you are considering.

I got fic 1250's on the way and I got the 255 high pressure... I wanted to match everything as close as possible because I have no intentions on going bigger. E85 isn't available within 50 miles so I'm sticking with 93.

Sounds good, the 1250's and high pressure 255 are even better, and should be all you need. Be sure to do follow up once you get everything installed and tuned.

Oh I will

The pressures you are refrencing is when the pressure relief valve opens in the pump it's fine for that turbo, but always keep an eye on lean conditions regardless.

My eyes are usually glued to the wideband when I'm doing a pull so what won't be a problem. I'll eventually buy an egt setup but for now I'm gonna tune a tad on the rich side.

My old fp green hta was 52 lb/min at 27 psi. A rewired 255 fuel pump will be enough. I added an inline bosch 044 just for insurance.

That's probably the path I'll take if this pump becomes a bottleneck.

Could just do the 450lph, good for 800whp on gas, never have to worry about a pump again

Order the 450 walbro, its only $99 right now on extremepsi for black Friday. I ordered mine yesterday, I have the FP green too but plan on upgrading later on so the 450 pump was perfect.

That was my original plan but I got a little rambunctious ordering parts this weekend and the 255hp was the biggest pump I could afford.

As long as you are staying on pump or race gas, you should be fine. I was running 29-30psi on the green with race fuel (850cc + 255 rewire) and still had room.

Well that's reassuring. Thanks.

See attached screenshot from log. Note the IDC's and Omni4bar. The tune could've used some work. I really didn't have much time to get it 100%, I was dealing with other issues and it was race day. Specs on my car were:

Automatic AWD 2g
Used FP Green (Not the newer HTA even)
2.3 Stroker
FP4R Cams
Evo 3 intake manifold
FP Exhaust Manifold
FIC 1250's
Walbro 450
E85, well E75 in the log..

My cams and turbo really wants to rev. As you could see my auto shifted at 7700 RPM and it was still making good power.

I know I have plenty injector... my concern was with the rewired 255 HP.

I'll me grabbing a 450 to run e 85 here rewired running a hx40. I plan on 30 psi to get her moving.

I believe if I were to rev out to 8k RPM and turned the boost up to 30psi I would be maxed out on my 1250's. But that was on e85. Since you're on 93 the pump and injectors will be fine. Just keep this in mind if you decide to switch to e85 though, you will hit the injectors limits.

I doubt we'll get e85 around here for quite some time but I'll definitely keep it in mind.

If u do get e85 why not just add another Walbro 255 and rewire it with a relay and hobb switch to turn on when in boost. Very cheap and simple to do. U can also run a ground to a pin on the ecu and use ecmlink's feature that people use to control nitrous to turn the second pump on when u like.